i spoke with former cia officer bob bear and sanjay gupta. bob, explain what one bomb could do? >> the standard shell is a 122 millimeter shell, standard artillery piece. if they were to drop this into a dense area of damascus, or a suburb of homs, doesn't matter which town, it would instantly kill 18,000 the first few minutes. >> just from one shell? >> go up there. one single shell would immediately kill 18,000 people. you know, this is a liquid. it's dispersed. it sticks on you. you get a few -- a little bit in your system and you're dead. >> sanjay, what does it do to somebody that comes in contact with it? >> it affects the particular receptors in the brain and let me preface it by saying it's odorless, tasteless and colorless and hard to know, you know, this it's there because of those things. and also by touching as bob was staying or inhaling it or water contaminated with it, you can also get poisoned. so you see, this is a substance that can affect you in many different ways and might know it's there. top from bottom, it's like the on switch on the body is turned on. th